Emma Watson has been hiding surprises for commuters on the London Underground - copies of her book club Our Shared Shelf's latest read.
The copies of Maya Angelou's Mom & Me & Mom will have messages from the actor in them, and some commuters have already found the books.
Ms Watson left the books down the sides of the escalators.
It seemed no one recognised her in the video she posted, and one user commented: "The sad thing is, everyone in London is in such a rush to get places I'm sure no one even recognised her!"